1. Field of the invention
This invention relates to control devices for electromechanically operated closure panels and the like, and more especially to actuating devices for sliding panels for the purpose of closing apertures, e.g. windows, doors, or roof openings, such as sliding roofs of vehicles, in which a reversible motor drives the movable parts by way of transmission elements.
2. Description of the Prior Art
U.S. Pat. No. 1,345,197 discloses a drive circuit for power operation of a movable part of a vehicle coachwork comprising a reversible motor supplied with current through a pole reversal switch and provided in the motor power supply circuit with switch means actuably by an impulse relay to which impulses are supplied through further (i.e. "second") switch means actuated by a control member movable by said motor when said control member reaches a prearranged position in its path of movement, said impulse relay being in parallel with said motor, and said relay controlled (i.e. "first") switch means being connected between one side of said impulse relay and one side of said motor.
This patent also discloses an actuating device for a movable part of a vehicle coachwork for the purpose of opening and closing apertures, which is provided with a motor which drives the movable part through transmission elements, a pole reversal switch for connecting terminals of the motor to different poles of a current source as required, an impulse relay, the control winding of which is connected in parallel with the motor, the relay (i.e. "first") switch being situated in a power supply lead to the motor and between the motor and the impulse relay, and a "second" switch for operating the impulse relay in one of the leads connecting the control winding of the impulse relay to a connecting lead between the motor and the pole reversal switch, the second switch being actuated by a control device driven by the motor which keeps the said switch closed while the movable coachwork part is in the closed position but open during the opening and closing of said part.
If a raisable sliding roof for a vehicle equipped with an operating mechanism according to the said Patent is raised or lowered into the closed position from a raised or retracted position by operating the pole reversal switch, it is possible, due to maladjustment or a high battery voltage, for the centrifugal force of the motor or roof to raise or lower the roof beyond the closed position. The second switch, operated via the control mechanism driven by the motor, is firstly closed in the closed position of the roof so that the impulse relay is operated and the first switch opened and then, through the further movement of the roof beyond the closed position, is opened again. As in this state both the first and second switches are open, the control winding of the impulse relay can receive no further pulse even if the pole reversal switch is operated again, so that the first switch cannot be closed and the motor cannot be supplied with power.